Antitampering device for receivers



Patented sept. 7,1926. Y

` UNITEDQSTATES 'PATENTOFFICB' DELMAB A. WHITSON, 0F LOS ANGELES,CALIFORNIA, ASSIGNOR TO\THE STENTOR- vPHONE COMPANY, OF LOS ANGELES,CALIFORNIA, A CORPORATION 0F CALIFOR- ANTITAMIPERING- DEVICE FORRECEIVVERS.

Application filed March'22, 1924. Serial No. 701,053.

`My present invention being referred to as an anti-tampering device forreceivers, it may-be understoo'drto be an object of thisV invention toprovide a means and a `method for preventing unqualified or unauthorizedkpersons from ,gaining access to delicate.instrumentgsuch as telephone'receivers, whether for the purpose of attempting to repair the samer orfor 4kany other purpose, such as the substitution of inferior or lesscostly parts for those to'which the favorable reputationV of y aninstrument maker may be due. p It is a particular object of this"invention to provide a construction or a method of closure suitable foruse in connection with instruments such 4 as loud speaking radioreceivers, or the" like, and effective to afford to a manufacturerpositive assurance as to whether or not a case or housing` elementenclosingl an instrument, which may have been returned as defective,has, in fact been opened; and,`in a preferred embodiment of myinvention, I may employ a case oi housing element or` a kcover elementprovided witha spring catch in a wholly iiiac-cefssiblepposition, thisspring catch being preferably adapted toprevent relative translatorymovement, of said case or housing and optionally provided withadditional vmeans, adapted to `,prevent a*V relative rotation thereof. fItlis anobje'ct of this invention to provide aninstrument of the generalcharacter referred to Vwith an anti-tampering device vcomprising a`catch which may automatically engage a keeper Whenevera case or housingis Vput in place, but which `can there- ,after be removed, Withoutdamage, only by `a suitable application of a soldering iron, or othermeans for a local application of heat, to a specifi-c sp'otintendcd tobe known only to a manufacturer and his employees Vor agents; andapreferred vembodiment of my inventionmay comprise a cover element, towhich the essentialsof aninstrument may be secured,V and a cooperatingcup-shaped case provided linitsbottom or base with `a slightly eccentric`and yielding pin having ahead vadapted to engage and interlock with a;substantially central aperturcd `element Whichfmay be vrigidly .orresiliently and `either Adirectly or indirectly connected with saidcover,-both said baseuand said pin being preferably tinned with a silveror hard solder in advance of the securing of said pin to said base, asby means involving the use of a ther objects of my invention will appearfrom the following description of an illustrative embodiment thereof andfrom the appended claims, taken in connection with the accompanyingdrawings, in whichlEig.l 1 is a substantially central vertical sectionthrough a receiver provided with my invention.

Fig. 2 is a sectional view taken substantially as indicated by the line2 2 of Fig. 1.

Figs 3 and t are slightly enlarged vdetailed views showing advantageousrelationships of securing elements hereinafter reierred to.

in Figs. 1 and 2.o-f thedrawings, I show my invention as appliedV to a:receiver 11,

which may be a loud speaker of a type now in common use. The loudspeaker 11 may comprise a mounting and cover element 12, to which theoperating parts of the instruments Ymay be attached. These operatingparts may include coils 14, supported from the.' mounting or coverelement 11 by a'suitable'bracket 15. An armature 16V may `vibrate thediaphragm 17 by means of the rod 18 and thereby produce sound. Toprotect the operating parts ofsuch instruments itis usualto employasuitable case 'or hous-7 ing, whichinay be in the' form of a cup 20provided with a base or lbottom 21 and ai cylindrical wall 22. `Ar`Thecase 20 may enclose any desired instrument or instrument-s and the edge25 may engage spacing arms or lugs 26 and may rest inside an annularconfining lip 27.

VThe parts just mentioned are in current use, and they form a part of mypresent invention only in the sense that they constitute anrorganization to which this invensecured eccentrically to the 'bottom 21of the i .cup 20 by soldering. When the cup 20 is in place, as in Figs.1 and 2, the pin may be arranged to extend through a substantially iii)central aperture. 3G, which may be provided in a keeper member rigidlyor resiliently and directly or indirectly connected with the cover ormounting element l2. In this instance, it is very convenient to providethe aperture SG in a keeper arm 37 Which is shown as being a part of theterminal bracket 3S of the speaker ll. rIhe axis oi' the pin 30 and theaperture 3G being relatively offset slightly, as shovvn, when this pinis projected through the aperture (which 'occurs when the cover is putin place) that portion of the aperture 36 indicated at li() may rest incontact With the neck 32 of the nin 30, and the shoulder il of the pinmay engage the upper surface otl the arm 37 as shown in Fig. 3. Theengagement betiveen the shoulder il and said surface holds the cupsecurely in place; and, if desired, the dimensions may be such that aresilient bottom 2l must be sprung upwardly to cause engagement bet-Weenthe shoulder 111 and the arm 37, this construction being effective toprevent all danger of the pins being` jarred from engagement.

As shotvn in Fig. d, to provide guidance for assembling and to preventsubsequent relative rotation, a. lip or projection t5 may be stamped inone of the lugs 96, and a suitable notch 46 may be formed in the vvall2Q of the cup Q0. Then the projection and the slot 46 engage, the pinand a 3c ture are properly aligned. `When the cup 20 is being installedin place, the cover is held so that the pin 30 assumes the position asindicated b y the dotted lines 50 in Fig. rThe projection 45 and theslot t6 being then aligned, the cup is forced in place; the conicalportion Se at this time enters the aperture 36, and the pin may yieldlaterally or it may spring the arm 3.7 to the left. as the pin is movedinwardly. Then the head has passed'tlnough the aperture 3G, the arm 37may spring bach to the position shown and thereby lock the cup 2Osecurely in place.

Then it is necessary to remove the cover for the purpose of adjustmentor repairs, an authorized person may do so by applying heat to thebottom of the cup 2O adjacent to the pin 30, a solderinO iron being verysuitable for this purpose. The application o1 heat melts the solder anddetaches the pin 30 from the cup, thereby allowing the cup to beremoved. Before the cup is replaced, the pin may be again soldered inplace, in order that the cup may again be rendered tamper-proof.

Although, I have herein described one complete embodiment of myinvent-ion, it will be understood that various features thereof might beindependently employed` and also that various modifications might bemade by those skilled in the art, without the slightest departure fromthe spirit and scope of my invention, as the same is indicated above andin the following claims.

I claim as my invention l. in an anti-tampering device for enclosinginstruments, the combination of a meinber; a case associated with saidmember; and means for preventing said member and said case frombeingseparated, said means being caused upon local application of heat torender separable Without ,damage said member and said case.

2. In an anti-tampering device for enclosing instruments, thecombination of: a cover member; a case associated With said cover memberto enclose instrument mechanisni; and means for preventing said covermember and said case from being separated, said means being caused onlyupon local application of heat to render separable ivithout damage saidmember and said case.

3; n an anti-tampering device for cnciosing instruments, the combinationof: a cover member; a case associated with said cover member; and meansfor preventing said member and said case from being separated, saidmeans comprising a soldered connection between contiguous portions ofsaid member and said case, said solder being caused upon localapplication of heat to soften and render separable without damage saidmember and said case.

li. ln an anti-tampering device for enclosing instruments, thecombination of: a cover member; one element of a catch secured to saidcover member; a case associated With said cover member; a second elementof a catch associated with said case and adapted to engage the iirstnamed catch element for preventing said cover member and said case frombeing separated, one of said catch elements being secured to itssupporting member with solder, the softening of said solder byapplication of heat being alone suliicient to render said cover memberand said case separable Without damage to parts.

5. In an anti-tampering device for enclosing instruments, thecombination of: a cover member; one element of a catch secured to saidcover member; a case associated With said cover member; a second elementof a catch associated with said case and adapted to engage the iii-stnamed catch element for preventing said cover member and said case frombeing separated, the second named catch element being secured to saidcatch with solder, the softening of said solder by application of heatbeing alone sutiicient to render said cover member and said caseseparable Without damage of parts.

6. In an anti-tampering device for enclosing instruments, thecombination of: a case element; a cover element normally extending oversaid case elementi; and resiliently related interlocking elementsrespectively secured to said case element and said cover element, saidinterlocking elements being inaccessible from the exterior of tlie caseand being arranged to function Without injuring any of the parts of tliecombination.

7. In an anti-tampering device for enclosing instruments, tliecombination of: a case element; a cover eleinentnornially extending nover said case eleinentgand resiliently related interlocking elementsrespectively secured to said case element and said cover element, one ofsaid interlocking elements being a resiliently supported catch, saidinterlocking elements being inaccessible from tlie exterior of the caseand being arranged to function Without injuring any of tlie parts oftlie combination. n

8. In anfaiiti-tanipering device for enclosing instruments, tliecombination of: a case.

i element; a cover element normally extending over said case element;and resiliently related interlocking elements inaccessible from tlieexterior of the ease respectively secured to said case element andsaidrcover element, one of said interlocking elements being aresilieiitly supported eatcli extending inwardly from tlie base of saidca-se and tlieotlierV being a keeper secured to said cover and adaptedto engage said catcli.

10. In an anti-tampering device for enclosing instruments, tliecombination of: a case element; a cover element normally extending oversaid case element; and resiliently related interlocking elementsinaccessible frointlie exterior of tlie case respectively secured tosaid case element and said cover element, one of said interlockingelements being a resiliently supported catcli extending inwardly fromtlie base of said case and the other being a keeper, secured to saidcover and adapted to engage said catch, eitlier said case or said keeperbeing eccentrically positioned. 1

11. In an anti-tampering device for enclosing instruments, tliecombination of: a case element; a cover element normallyl extending oversaid case element; resiliently related interlocking elementsinaccessible from the exteriorv of tlie case respectively secured tosaid case element and said cover element; and nieans for preventingrelative f rotation of said case vand said cover, said means beingarranged to function Without injuring any of the parts of thecombination.

